Thesis (M.S.)--University of Michigan, 1981.

Thesis (Ph.D.) - University of Queensland, 2003. / Includes bibliography.

Thesis (Ph.D.)--University of Western Sydney, 2008. / A thesis submitted to the University of Western Sydney, College of Health and Science, School of Nursing in fulfilment of the requirements for the degree of Doctor of Philosophy. Includes bibliographical references.

Hyperbaric Oxygen Therapy (HBOT) is an old technology which has acquired value in chronic wound care. HBOT is known to promote local and systemic healing effects by improving the oxygenation of the wound tissue. The increased tissue oxygenation hastens removal of the bacterial bioburden, which allows resolution of inflammation and facilitates matrix production, cell division, and ultimately wound closure. Staphylococcus aureus is the most frequently isolated organism from Diabetic Foot Infections (DFI). Therefore, our lab chose to use the treatment paradigm of HBOT to initially look at the single species level as to how HBOT affects S. aureus. DFI are primarily polymicrobial, so the responses of bacterial communities to this therapy were also considered. Previous research focused solely on host response to HBOT, but our pilot testing indicates that HBOT also exhibits a bacterial response. Initial testing with S. aureus indicated that HBOT can create growth defects in bacteria in vitro. In preliminary experiments, our lab discovered that bacterial culture on solid medium is greatly altered under the pressure of hyperbaric oxygen. Normal robust growth and pigmentation are seen in S. aureus cultured in ambient conditions. However, when the same strain is cultured under HBOT conditions, there is a marked decrease in pigmentation and colony size. When other species were exposed to HBOT conditions, growth on solid media was significantly diminished. Interestingly, K. pneumoniae is able to grow normally under HBOT conditions. Normal air mixtures at the increased pressure do not have any discernable effect on bacterial growth, and the limiting effects of oxygen are not seen unless used at the increased pressure. In a broth macrodilution MIC assay, various antibiotics show an increase in susceptibility after exposure to HBOT. Lastly, biofilm formation is altered under HBOT conditions, further supporting a bacterial adjustment to HBOT and an altered mode of growth. In order to better understand the effects of a high pressure high oxygen environment on the bacterial bioburden, this study investigates the effects of HBOT on bacterial species comprising a chronic wound. Primary data has suggested that HBOT increases susceptibility of antibiotics, and can alter bacterial transcription to hinder growth of many organisms. We hypothesize that Hyperbaric Oxygen Therapy affects diabetic foot infections by changing the healing process via transcriptional alteration of bacterial species in the wound. Furthermore, we hypothesize that HBOT alters the efficacy of some antibiotics as well as affecting the biofilm capacity of many bacterial species.

Administration of nasal cannula therapy tasks providers with periodically monitoring their patients and adjusting settings according to patient needs. Conventionally, providers monitor a patient's oxygen demand using pulse oximetry and a qualitative assessment of the patient's work of breathing. The motivation for this research is to augment the traditional qualitative assessment of work of breathing with a quantitative measurement of a patient's tidal volume, the volume of air inhaled with each breath. This thesis presents a novel approach to measure tidal volume using a nasal cannula with built-in pressure sensors. Pressure waveforms obtained from continuous measurement of the pressure at the tip of the cannula are used to estimate nasal flowrates, and these nasal flowrates are time-integrated to estimate tidal volumes. Computational fluid dynamics (CFD) models were used to simulate fluid flow in a simplified nasal passage undergoing nasal cannula therapy. These simulations used a range of flow conditions characteristic of both low-flow and high-flow nasal cannula treatments. The simulations produced a transformation from cannula tip pressure to instantaneous nasal flowrate, and this transformation was evaluated using a matching empirical experiment. This empirical experiment used a matching physical geometry with a similar range of flow conditions, and the transformation obtained from CFD was able to estimate the actual tidal volumes with 85% accuracy. This study showed that continuous pressure measurement at the tip of a nasal cannula produces enough information to estimate nasal flowrates and tidal volumes. No similar studies were found during the literature review, so an accuracy of 85% is promising for this stage. If this technique could be made more accurate and deployed in an unobtrusive way, the resulting nasal cannula device could be used to continuously, comfortably monitor patients' tidal volumes. / Master of Science / Oxygen therapy is the most common prescription in hospitals across the United States, and the most common form of oxygen therapy is nasal cannula therapy. Administration of nasal cannula therapy requires providers to periodically assess their patients' oxygen saturations and work of breathing. Oxygen saturation can be quantitatively monitored using pulse oximetry but work of breathing must be qualitatively monitored using visual exams or walking tests. The motivation of this research is to augment this qualitative assessment with a quantitative metric. In our research, we chose the volume of inhaled air (the "tidal volume") as a proxy metric for a patient's work of breathing. This thesis presents our attempt to use a nasal cannula augmented with pressure sensors to estimate the tidal volume of a mannequin undergoing nasal cannula therapy. Our concept is that more intense inhalations/exhalations produce larger pressure swings at the tip of the nasal cannula. For this proof-of-concept study, a simplified nasal passage geometry was used. Pressure waveforms obtained from continuous measurement of the pressure at the tip of the cannula are used to estimate nasal flowrates, and these nasal flowrates are time-integrated to estimate tidal volumes. Computational fluid dynamics (CFD) simulations were used to predict how the cannula tip pressure changes as a function of nasal flowrates and cannula flowrates, then this relationship was tested using a matching empirical experiment. This matching empirical experiment showed that our technique of estimating tidal volumes was 85% accurate. This study showed that continuous pressure measurement at the tip of a nasal cannula produces enough information to estimate nasal flowrates and tidal volumes. No similar studies were found during the literature review, so an accuracy of 85% is promising for this stage. If this technique could be made more accurate and deployed in an unobtrusive way, the resulting nasal cannula device could be used to continuously, comfortably monitor patients' tidal volumes.

Thesis (MScMedSc)--Stellenbosch University, 2012. / ENGLISH ABSTRACT: A survey was conducted between 3 August and 5 October 2011 to test and evaluate the knowledge and attitudes of the military and civilian medical practitioners at the royal medical Service in the kingdom of Bahrain with regards to the clinical application of hyperbaric oxygen therapy. The survey consisted of a questionnaire and a semi-structured interview in which a total of 93 (out of a possible 302) medical practitioners were included (13 participated in the interviews). Similar to findings of previous studies, the knowledge of medical practitioners in Bahrain regarding hyperbaric oxygen therapy was low. Several practitioners were able to mention at least one indication for the therapy. No single factor had a statistically significant association with knowledge or the lack thereof. A large proportion of the participants had a positive attitude towards the use of hyperbaric oxygen therapy, felt that it is a valid treatment modality and they would refer their patients for such treatment. They would like to receive more information on hyperbaric oxygen therapy. Educational interventions to address the knowledge gap would likely be effective, since most participants have a positive attitude towards the therapy and believe that it is cost-effective.

The present research sought to understand patient experiences during Hyperbaric Oxygen Therapy (HBOT) by using 24 HBOT patients (17 men, 7 women) to examine the relationship between individual variables and anxiety, and providing One Session Exposure Therapy (OSET; Öst, 1989) if necessary. Pre-HBOT participants completed the following measures: State-Trait Anxiety Inventory (STAI; Spielberger, 1983), Claustrophobia Questionnaire (CLQ; Radomsky, Rachman, Thordarson, McIsaac, & Teachman, 2001), Anxiety Sensitivity Index (ASI; Reiss, Peterson, Gursky, & McNally, 1986), and Treatment Credibility/Expectancy Questionnaire (CEQ; Devilly & Borkovec, 2000). State Anxiety was assessed pre-HBOT and at the tenth and last sessions. Findings suggest Dispositional Anxiety (STAI-Trait + ASI), Expectancy of symptom improvement (CEQ), and gender were significantly predictive of State Anxiety before and during HBOT. Limitations and directions for future research are discussed.

As investigações sobre os efeitos da oxigenoterapia hiperbárica (OHB) em lesão por ruído são escassas e apontam para diferentes efeitos em função do momento de intervenção. Dentre os trabalhos já descritos foi observado efeito lesivo da OHB quando aplicada imediatamente ao trauma acústico, contudo, efeito positivo foi observado quando aplicada após 2 e 6 horas. Com relação aos tratamentos usados para trauma acústico, alguns estudos descrevem o uso de corticoides como melhor alternativa, mas recentemente estudos apontam para a sua combinação com OHB como a terapêutica com maior beneficio nas lesões por ruído. O presente estudo teve como objetivos avaliar o momento da intervenção pela OHB após 2, 4 e 6 horas de repouso auditivo após exposição ao ruído e avaliar a associação terapêutica entre a OHB e corticoterapia (CT). Cobaias albinas foram expostas a um ruído branco na faixa de 4 kHz com intensidade igual a 110dB NPS por 72h e divididas em cinco grupos terapêuticos: OHB com início após 2, 4 e 6h de repouso auditivo após exposição ao ruído, CT isolada e OHB após 6 horas de repouso associada a CT. O tratamento durou 5 dias, sendo uma sessão terapêutica por dia. Todos os animais tiveram a função auditiva avaliada pelo Potencial Evocado Auditivo de Tronco Encefálico (PEATE) e pelas Emissões Otoacústicas Produtos de Distorção (EOAPD) em três momentos: pré-ruído, pós-ruído e pós-tratamento. Após a eutanásia dos animais e preparação dos espécimes cocleares, todas as cócleas foram analisadas através de Microscopia Eletrônica de Varredura (MEV). Não houve diferença estatística significativa entre os momentos de intervenção pela OHB após 2, 4 e 6 horas, contudo, os dados de MEV demonstraram que uma maior otoproteção ocorreu quando a intervenção foi realizada após um maior repouso auditivo. Apesar da não diferença estatística significativa, os achados anatômicos e funcionais permitiram concluir que a associação terapêutica entre a OHB e a corticoterapia desempenhou um melhor efeito otoprotetor e terapêutico se comparada a essas mesmas terapias isoladas. / Investigations on the effects of hyperbaric oxygen therapy (HBOT) in noise injury are scarce and point to different effects depending on the time of intervention. Among the work already described has been observed damaging effect of HBOT when applied immediately after the acoustic trauma, however, positive effect was observed when applied after 2 and 6 hours of rest after the trauma. Studies describe the use of corticosteroids as the best alternative to treat acoustic trauma, but recent studies point to their combination with HBOT as the major benefit in lesions by noise. This study aimed to evaluate the time of intervention by HBOT after 2, 4 and 6 hours of rest after hearing noise exposure and to evaluate the association between HBOT and corticoid. Female guinea pigs were exposed to a white noise on 4kHz at 110dB SPL during 72 hours and divided into five treatment groups: HBOT after 2, 4 and 6 hours of rest after the noise exposure, corticosteroid therapy and HBOT combined with corticoid. The treatment lasted five days, being a therapy session per day. All animals were exposed to Distortion Product Otoacoustic Emissions (DPOAE) and Auditory Brainstem evoked Response (ABR) in three moments: before and after exposure to the noise and after the treatment. All cochleae were examined by scanning electron microscopy (SEM). There was no statistically significant difference between the moments of intervention by HBOT after 2, 4 and 6 hours, however, the SEM data showed that a greater otoprotection occurred when the intervention was performed after a higher auditory rest. Although not statistically significant, the anatomical and functional findings concluded that the association between HBOT and corticosteroid therapy played a better otoprotective and therapeutic effect compared to those same therapies alone.

As investigações sobre os efeitos da oxigenoterapia hiperbárica (OHB) em lesão por ruído são escassas e apontam para diferentes efeitos em função do momento de intervenção. Dentre os trabalhos já descritos foi observado efeito lesivo da OHB quando aplicada imediatamente ao trauma acústico, contudo, efeito positivo foi observado quando aplicada após 2 e 6 horas. Com relação aos tratamentos usados para trauma acústico, alguns estudos descrevem o uso de corticoides como melhor alternativa, mas recentemente estudos apontam para a sua combinação com OHB como a terapêutica com maior beneficio nas lesões por ruído. O presente estudo teve como objetivos avaliar o momento da intervenção pela OHB após 2, 4 e 6 horas de repouso auditivo após exposição ao ruído e avaliar a associação terapêutica entre a OHB e corticoterapia (CT). Cobaias albinas foram expostas a um ruído branco na faixa de 4 kHz com intensidade igual a 110dB NPS por 72h e divididas em cinco grupos terapêuticos: OHB com início após 2, 4 e 6h de repouso auditivo após exposição ao ruído, CT isolada e OHB após 6 horas de repouso associada a CT. O tratamento durou 5 dias, sendo uma sessão terapêutica por dia. Todos os animais tiveram a função auditiva avaliada pelo Potencial Evocado Auditivo de Tronco Encefálico (PEATE) e pelas Emissões Otoacústicas Produtos de Distorção (EOAPD) em três momentos: pré-ruído, pós-ruído e pós-tratamento. Após a eutanásia dos animais e preparação dos espécimes cocleares, todas as cócleas foram analisadas através de Microscopia Eletrônica de Varredura (MEV). Não houve diferença estatística significativa entre os momentos de intervenção pela OHB após 2, 4 e 6 horas, contudo, os dados de MEV demonstraram que uma maior otoproteção ocorreu quando a intervenção foi realizada após um maior repouso auditivo. Apesar da não diferença estatística significativa, os achados anatômicos e funcionais permitiram concluir que a associação terapêutica entre a OHB e a corticoterapia desempenhou um melhor efeito otoprotetor e terapêutico se comparada a essas mesmas terapias isoladas. / Investigations on the effects of hyperbaric oxygen therapy (HBOT) in noise injury are scarce and point to different effects depending on the time of intervention. Among the work already described has been observed damaging effect of HBOT when applied immediately after the acoustic trauma, however, positive effect was observed when applied after 2 and 6 hours of rest after the trauma. Studies describe the use of corticosteroids as the best alternative to treat acoustic trauma, but recent studies point to their combination with HBOT as the major benefit in lesions by noise. This study aimed to evaluate the time of intervention by HBOT after 2, 4 and 6 hours of rest after hearing noise exposure and to evaluate the association between HBOT and corticoid. Female guinea pigs were exposed to a white noise on 4kHz at 110dB SPL during 72 hours and divided into five treatment groups: HBOT after 2, 4 and 6 hours of rest after the noise exposure, corticosteroid therapy and HBOT combined with corticoid. The treatment lasted five days, being a therapy session per day. All animals were exposed to Distortion Product Otoacoustic Emissions (DPOAE) and Auditory Brainstem evoked Response (ABR) in three moments: before and after exposure to the noise and after the treatment. All cochleae were examined by scanning electron microscopy (SEM). There was no statistically significant difference between the moments of intervention by HBOT after 2, 4 and 6 hours, however, the SEM data showed that a greater otoprotection occurred when the intervention was performed after a higher auditory rest. Although not statistically significant, the anatomical and functional findings concluded that the association between HBOT and corticosteroid therapy played a better otoprotective and therapeutic effect compared to those same therapies alone.

Orientador: Susana Erico Tanni Minamoto / Coorientador: Irma de Godoy / Banca: Ilka Lopes Santoro / Banca: Hugo Hyung Bok Yoo / Resumo: A insuficiência respiratória costuma estar presente no quadro clínico de pacientes com doença pulmonar avançada, como a doença pulmonar obstrutiva crônica (DPOC), doença pulmonar intersticial (DPI) e hipertensão pulmonar (HP). A oxigenoterapia domiciliar prolongada (ODP) faz parte do tratamento e está associado no controle da progressão da doença e na sobrevida. Entretanto, há poucos dados na literatura sobre o efeito da ODP na evolução da doença em pacientes de diversas patologias pulmonares e que apresentam hipoxemia arterial transitória ao esforço. Avaliar as características evolutivas de pacientes de diversas patologias pulmonares e portadores de hipoxemia transitória ao esforço que utilizam ODP durante o sono e aos esforços no período de um ano. Foram acompanhados 60 pacientes com DPOC, 16 com DPI e 15 com HP. A hipoxemia transitória ao esforço foi confirmada pelo teste de caminhada de seis minutos (TC6) e pela gasometria arterial em repouso. Para todos os pacientes foi indicada suplementação de ODP 0,5L/min por 12h/dia que incluísse os períodos de esforço e durante o sono. No momento basal e após um ano os pacientes foram avaliados em relação aos fármacos pulmonares utilizados, a comorbidades pelo índice de Charlson, a composição corporal, a espirometria, a oximetria de pulso (SpO2), a gasometria arterial, hemograma, a qualidade de vida através do questionário de qualidade de vida na doença respiratória do Hospital Saint George (SGRQ), o índice de dispneia pelo índice basal de dispneia (BDI) e Medical Research Council Modificado (MMRC), escore de ansiedade e depressão, TC6 com suplementação de ODP, aderência ao tratamento, frequência de exacerbação e óbitos. Foi realizada a análise descritiva dos dados, comparação entre os momentos nos pacientes que mantiveram hipoxemia transitória ao esforço e suas associações dos grupos de DPOC, DPI e HP. Além disso, foi realizada análise ... / Abstract: Respiratory failure is usually present in clinical status of patients with advanced lung disease such as chronic obstructive pulmonary disease (COPD), interstitial lung disease (ILD) and pulmonary hypertension (PH). Long Term Oxygen Therapy (LTOT) as part of the treatment and is associated with control of disease progression and survival. However, there are little data in the literature about the effect of the LTOT in disease progression in patients with chronic lung diseases and exertional desaturation. Evaluate the influence of LTOT used during sleep and exertion in characteristics of patients with chronic lung diseases and exertional desaturation followed for one year. We evaluated 60 patients with COPD, 16 with ILD and 15 with PH. The exertional desaturation was confirmed by the six-minute walk test (6MWT) and the room air arterial blood gases. All patients received a recommendation to use 0.5 L/min during 12h/day of LTOT, including sleep and exertion periods. At baseline and after one year we assessed pulmonary pharmacological treatment, adherence to treatment, comorbidities by the Charlson index, body composition, spirometry, pulse oximetry (SpO2), arterial blood gas analysis, CBC, 6MWT supplemented with LTOT, Saint George Respiratory Questionnaire (SGRQ), dyspnea sensation according to baseline dyspnea index (BDI) and the Modified Medical Research Council (MMRC), score of anxiety and depression, frequency of exacerbation and mortality rate. We performed descriptive analysis of data comparing the moments of patients who presented stable exertional desaturation according to the group (COPD, ILD and PH patients). We compared groups according to the presence of stable exertional desaturation or severe hypoxemia and death. 39 patients with COPD, 11 with ILD and 11 with PH showed stable exertional desaturation. We observed that patients with stable exertional desaturation showed symptom improvement after one year, however, it was not ... / Mestre